= Solution
Assuming that the two listed <leptonic decay> categories exhaust the leptonic modes, the inclusive hadronic <branching fraction> is $100-17.83-17.41=64.76\%$. Thus
$$
R_\tau=\frac{\Gamma(\tau\to\text{hadrons}\,\nu)}{\Gamma(\tau\to e\bar\nu_e\nu_\tau)}=\frac{64.76}{17.83}=3.632.
$$
At the simplest massless <quark> level, the <W boson> couples to $u\bar d$ and $u\bar s$ in three <color charge> states, so equal quark and <lepton> weak <coupling constant (physics)> values predict
$$
\boxed{R_\tau^{(0)}=N_c(|V_{ud}|^2+|V_{us}|^2)\simeq3.0024\simeq3}.
$$
This is a rough check of <color multiplicity in a decay width> and universal weak-current normalization. It is much less precise than the two-<lepton> ratio because hadronic <Quantum chromodynamics> and <electroweak interaction> corrections are sizeable: the data require a net correction factor near $3.632/3.0024\simeq1.21$. They must be included before extracting a quark-to-<lepton> <coupling constant (physics)> ratio. It would be incorrect to interpret the excess over three directly as a failure of weak universality. The displayed exclusive hadronic modes alone would underestimate the inclusive sum.
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